print("加法：80-100，减法：50-79.乘法：20-49，除法：0-19")
num1 = eval(input("请输入第一个数字："))
num2 = eval(input("请输入第二个数字："))
if 0 <= num1 and num2 <= 100:
    if 80 <= num1 <= 100 and 80 <= num2 <= 100:
        print(f"两数相加：{num1 + num2}")
    elif 50 <= num1 <= 79 and 50 <= num2 <= 79:
        if num1 > num2:
            print(f"两数相减等于：{num1 - num2}")
        else:
            print(f"两数相减等于：{num2 - num1}")
    elif 20 <= num1 <= 49 and 20 <= num2 <= 49:
        if num1 == num2:
            print(f"两数平方等于：{num1 ** 2}")
        else:
            print(f"两数相乘等于：{num1 * num2}")
    elif 1 <= num1 <= 19 and 1 <= num2 <= 19:
        print(f"两数相除等于：{num1 / num2}")
    else:
        print("被除数不能为零")
else:
    print(f"第一个数是{num1},第二个数是{num2}")

